I guess you need to put together two things in this question, your capability and the needs of potential customers. Your capability is going to drive a great conversation as long as you know very well the subject. The people that have some needs that are related with your capability are going to start talking about their problems and pains and here is when the magic happens. You have great conversations because people is interested to get some expertise from outside and if you are the people that can solve it, they will be willing to provide information to solve the problem. Once you find several people with the same UNSOLVED problem, then you have a niche opportunity. Just validate that they did not found some solutions because the solution does not exist and not because they search in the wrong place.